I'm voting for Kane mainly because of the shear whining I've seen in favor of Mick Foley. Boo, Hoo, Mrs. Foley's baby boy is losing to a guy who.. was overall more relevant with one gimmick, than Foley really was with 4. Moving on.
Mankind was Foley's best gimmick, but overall unless he was facing the Undertaker he really didn't do much at all. He lost just as much as Kane, and he wasn't half as dominating as Kane was in the first year he was in the Company.
So I see some people tossing up Kane losing a lot. Uhm, when he debuted - he squashed the shit out of a Mick Foley version of Mankind that had yet to truly accomplish the WWF Championship glory he would gain little over a year later. So this is where someone claims Foley wasn't yet in his prime.
But then there was Cactus Jack. Who most people will remember the most as being relevant whenever a weapon was legal in a match; but then if I just stopped there I wouldn't be giving the guy who actually did something decent in WCW his proper credit, would I?
Wait though, there's more. Someone could defend Dude Love in this situation, right? Well. Good luck.
Finally, you have Mick Foley himself - the guy who technically was considered as winning the WWF Championship, only to go on a back and forth game of who can rack up more meaningless reigns, with the Rock.
When you boil this down to the bottomline - Foley was every bit as relevant during Kane's domination over him in the majority of their single's matches, as anywhere (or as anyone) else. I don't give a shit if Kane was horrible as a dentist, or sucked as a fake Diesel. He gains my vote - because there isn't a video I've seen yet that shows me how Foley has ever stood a snowballs chance in hell against Kane.